Mrs Longhurst said: "My daughter Sue and myself are very pleased that after 30 months of intensive campaigning we have persuaded the government to take action against these horrific internet sites, which can have such a corrupting influence and glorify extreme sexual violence."

Jane Longhurst, 31, was found dead on Wiggonholt Common, near Pulborough, West Sussex, on 19 April 2003.

She had been strangled with a pair of tights and her body kept in storage for weeks before it was found.

In 2004, musician Coutts, 36, of Waterloo Street, Hove, West Sussex, was jailed for life for her murder but on appeal the minimum term he was ordered to serve was reduced from 30 to 26 years.

Such material has no place in our society

Home Office minister Vernon Coaker

Trial jurors had been told of his obsession with strangulation and how he looked at internet sites connected with the fetish.

It is already a crime to make or publish such images but proposed legislation will outlaw possession of images such as "material featuring violence that is, or appears to be, life-threatening or is likely to result in serious and disabling injury".

Home Office Minister Vernon Coaker MP said: "Such material has no place in our society but the advent of the internet has meant that this material is more easily available and means existing controls are being by-passed - we must move to tackle this."

Mrs Longhurst said legislation, which would apply to all websites, would mean her daughter's death had not been "entirely in vain".

Reading West MP Martin Salter, who backed the campaign, said: "This campaign has taken a huge amount of time and effort but it has struck a chord right across the country.

Graham Coutts was said to have been addicted to violent porn

The move by the government would close a legal loophole.

"It is great news that the Government has not only listened but has responded to calls to outlaw access to sickening internet images, which can so easily send vulnerable people over the edge."

The new law will not target those who accidentally come into contact with obscene pornography or affect mainstream entertainment industry working within current obscenity laws.

But the proposed legislation has drawn opposition from anti-censorship groups and organisations who represent people involved in sadomasochist activities.

Shaun Gabb, director of the anti-censorship organisation the Libertarian Alliance, said: "If you are criminalising possession then you are giving police inquisitorial powers to come into your house and see what you've got, now we didn't have this in the past."

This year five Law Lords sent Coutts' case back to the Court of Appeal to "invite that court to quash the conviction".

It was argued that jurors in the original trial should have been offered the option of manslaughter as well as a murder verdict.